1. The Field of Invention.
The present invention has to do with the manufacture of tampons and more specifically with the continuous formation of rosette shaped tampons from aggregate containing tubular sacks or overwraps having a withdrawal string at one end, followed by the assembly of the tampons with a two-piece tube-type inserter by means of which the tampon may be inserted into a vagina.
2. Description of the Prior Art.
Tampons of the type to which this invention relates are disclosed in commonly owned U.S. Pat. No. 3,815,601, dated June 11, 1974, and entitled "Catamenial Aggregate Absorbent Body." In accordance with the teachings of the said patent, the tampon comprises aggregate composed of individual pieces of absorbent, foam-like material encased within a flexible, fluid-permeable overwrap in the form of a tubular sack closed at its opposite ends, the ends of the sack preferably being gathered inwardly and secured to form end seals. A withdrawal string is attached to one end of the sack, which is preferably elongated, and the sack is inverted to form it into rosette shape by displacing inwardly the distal end of the sack, i.e., the end of the sack opposite the withdrawal string is displaced inwardly to form a cavity in the overwrap, thereby forming a tampon structure in which the absorbent aggregate is encased by an overwrap having an exterior portion forming the exterior surface of the tampon and a re-entrant portion forming the surface of the cavity. Following formation of the tampon into rosette shape, it is radially compressed and enclosed in a tube-type inserter having a head or outer part in which the the tampon is contained and an inner or plunger part by means of which the tampon is expelled from the inserter.
Mechanism and procedures for forming and filling tampon sacks of the character described are disclosed in commonly owned United States Application Ser. No. 484,813, in the name of Jean E. Schaefer, filed July 1, 1974 and entitled "Apparatus And Method For Continuously Forming And Filling Tampon Sacks," now U.S. Pat. No. 3,982,374, issued Sept. 28, 1976. In accordance with the teachings of this application, a web of sack forming material is printed with adhesive at spaced apart intervals at which end seals for the sacks are to be formed, the adhesive dried, and the web tubed around a hollow mandrel with the longitudinal edges of the web overlapped and sealed to form the longitudinal seam of the tubing. The tubing is fed to a rotating turret having a plurality of pleating and sealing stations which sequentially engage and gather the tubing and seal it together in the areas of the previously applied adhesive to form a continuous series of sacks. As the leading end seal of each successive sack is formed, a charge of aggregate is introduced into the tubing through the mandrel around which it is formed and propelled through the tubing so that the material comes to rest against the leading end seal of the sack being formed, whereupon the formation of the next successive end seal completes the sack and encloses the deposited charge of material. The sacks so-formed may then be provided with withdrawal strings which are stitched or tied to one of the end seals and the sacks cut apart to form individual units.
In another form of apparatus disclosed in commonly owned U.S. application Ser. No. 517,110 by Ronald W. Kock, filed Oct. 22, 1974 and entitled "Loop Knot Tying Method And Apparatus", now U.S. Pat. No. 3,940,169, issued Feb. 24, 1976, the tampon sacks may be fabricated on a rotating device carrying a plurality of operating heads which, in addition to pleating and sealing the web at spaced apart intervals to form sacks, is provided with means for attaching withdrawal string, including means for metering the correct length of string, cutting the string, piercing the sack in the area of an end seal, forming a loop knot through the pierced hole in the end seal, and severing the sacks intermediate the end seals to provide individual tampon sacks suspended by their withdrawal strings for discharge from the device.
The transfer mechanism of the present invention is specifically designed to engage the strings of tampon sacks fabricated on the apparatus just described and transfer them to the assembly turret for conversion into finished products.
Reference is also made to commonly owned co-pending application Ser. No. 400,620, by Delmar R. Muckenfuhs, filed Sept. 25, 1973, and entitled "Device And Method For Forming Tampon," now U.S. Pat. No. 3,875,615, issued Apr. 18, 1975, which teaches the formation of the closed tubular sacks into rosette shape. A cylindrical holding chamber is provided into which the tubular sack is inserted and expanded radially outwardly by a vacuum drawn on the holding chamber, a reciprocating tubular plunger sequentially acting to guide the sack into the holding chamber, displace the distal end of the sack inwardly to form it into rosette shape, and thereafter eject the shaped tampon from the holding chamber. Aspects of this invention are utilized in the present invention to effect formation of the sacks into rosette shape.